Where do the air bubbles on the bottom come from when you boil water?

Question

Where do the air bubbles on the bottom come from when you boil water?

In: 42

Answer 1

At first the bubbles are air that has dissolved in the water. Hot water isn’t as good at dissolving air so heating the water drives the air out, forming air bubbles on the edge of the container. Once the water is fully boiling, the bubbles are not of air but of steam, which is to say water vapour.